The Study
Protein intake and risk of urolithiasis and kidney diseases: an umbrella review of systematic reviews for the evidence-based guideline of the German Nutrition Society
This study looked at lots of other studies to see if eating more protein hurts your kidneys. It found that protein makes some kidney markers go up, but those changes might just be your kidneys working normally, not getting damaged. It didn't find proof that protein causes kidney stones or disease.
Analysis score
Maximum 85 for a systematic review with meta-analysis.
Where the score came from
This study looked at many previous studies to see if eating more protein than recommended (over 0.8g per kg of body weight) damages your kidneys.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 553 / 100
Quality score
Systematic reviews and meta-analyses of cohort studies. They sit above a single cohort study but below a single randomized trial, because the underlying evidence is still observational.
Key takeaways
Summary
Based on the study abstract and findings.
- 1These changes are normal kidney responses to more protein, like a car engine revving higher when you press the gas — not a sign of damage.
- 2Eating more protein makes your kidneys filter more blood (+7.2 mL/min), puts out more calcium in urine (+25 mg/day), and raises urea levels (+1.75 mmol/L), but doesn't increase protein in urine or kidney stones.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
European Journal of Nutrition
Year
2023
Authors
T. Remer, Nicole Kalotai, A. M. Amini, Andreas Lehmann, Annemarie Schmidt, H. Bischoff-Ferrari, S. Egert, S. Ellinger, A. Kroke, T. Kühn, S. Lorkowski, K. Nimptsch, L. Schwingshackl, A. Zittermann, B. Watzl, R. Siener
Related Content
Claims (7)
Eating a high-protein diet does not damage the kidneys in people with healthy kidney function, even though it raises levels of creatinine and urea in the blood.
Eating a high-protein diet does not make chronic kidney disease worsen faster in people with mild to moderate kidney impairment.
In healthy adults, consuming more than 0.8 grams of protein per kilogram of body weight per day does not lead to increased urinary albumin excretion, even though glomerular filtration rate and calcium excretion rise.
In healthy adults, consuming more than 0.8 grams of protein per kilogram of body weight per day is linked to a measurable increase in kidney filtration rate by about 7.2 mL/min/1.73 m², and this change is not associated with kidney damage over periods of up to 24 months.
In healthy adults, eating more protein for a short time does not lead to chronic kidney disease, even though it temporarily changes kidney function markers like filtration rate and urea levels.
When healthy adults consume more than 0.8 grams of protein per kilogram of body weight per day, their blood urea levels rise by about 1.75 mmol/L due to normal protein metabolism, and this rise does not indicate kidney damage.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.